Stepped Attenuation Ladder With Constant dB Steps
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Solution Overview
Problem
Existing amplifier and attenuator designs require complex switching arrangements or numerous resistor values to achieve equal decibel steps, which is inefficient and costly.
Innovation Solution
A stepped attenuation circuit using a ladder network with only three different resistor values, where each stage provides a constant decibel step, allowing for simple and inexpensive implementation of equal dB steps by configuring resistors in an 'L' configuration with specific resistance values.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If complicated switching arrangements with a few different resistor values are used, then the number of resistor values is reduced, but the switching arrangement complexity increases
Solution Approach 1:
The patent changes the parameter of resistor values from a few different values to exactly three different values (R1, R2, R3), and simultaneously changes the switching arrangement from complicated to a simple single-pole multi-throw switch. This parameter change resolves the contradiction by finding an optimal balance between the number of resistor values and switching complexity.
Solution Approach 2:
The patent applies local quality by assigning specific functions to each of the three resistor values in the ladder network. R1 resistors are placed at specific positions, R2 resistors at other positions, and R3 resistors at remaining positions, creating a structured local distribution that achieves constant dB steps while simplifying the overall design.
2Device complexity
If a simple switching arrangement with many different resistor values is used, then the switching arrangement is simplified, but the number of different resistor values increases
Solution Approach 1:
The patent constrains the parameter of resistor values to exactly three different values (R1, R2, R3) while maintaining a simple single-pole multi-throw switching arrangement. This parameter constraint resolves the contradiction by preventing the number of resistor values from becoming excessive while keeping the switching arrangement simple.
Solution Approach 2:
The three resistor values (R1, R2, R3) serve multiple functions within the ladder network structure. Each resistor type contributes to multiple stage configurations, allowing the simple switching arrangement to achieve multiple attenuation levels with constant dB steps without requiring many different resistor values.
3Manufacturing precision
If N different resistor values are used to construct a series of N resistors, then the gain or attenuation steps are achieved, but the number of resistor values and switching complexity increase
Solution Approach 1:
The patent changes the parameter from N different resistor values to exactly three different resistor values (R1, R2, R3) arranged in a ladder network. This parameter change maintains precise constant dB steps between stages while dramatically reducing the number of different resistor values required.
Solution Approach 2:
The patent segments the attenuation circuit into multiple stages, where each stage contains a specific configuration of the three resistor types. This segmentation allows the ladder network to achieve precise gain or attenuation steps through the systematic arrangement of R1, R2, and R3 resistors across different stages.
4Manufacturing precision
If double pole, double throw switches are used in pi or T sections, then the attenuation levels are achieved, but the switching arrangement complexity increases
Solution Approach 1:
The patent changes the switching parameter from double pole, double throw switches to a simple single-pole multi-throw switch. This parameter change simplifies the switching arrangement while the ladder network configuration of three resistor types maintains the required attenuation levels with constant dB steps.
Solution Approach 2:
The patent merges the functions of multiple switches into a single single-pole multi-throw switch that can selectively connect to different taps on the ladder network. This merging eliminates the need for complex double pole, double throw switch arrangements while maintaining precise attenuation control through the structured R1, R2, R3 resistor configuration.
Data Source
AI summary
An attenuation circuit with stages having constant dB steps between stages is provided. The attenuation circuit can be configured as a ladder network using resistors having three different values. A first resistor can be connected between the last stage of the attenuation circuit and ground and have a first predetermined resistance. One or more second resistors can be connected in each stage and have a second predetermined resistance based on the first predetermined resistance and the dB step between stages. One or more third resistors can be connected in parallel to the first resistor for the remaining stages and have a third predetermined resistance based on the first predetermined resistance and the dB step between stages.